GM Service Manual Online
For 1990-2009 cars only

A first order tire and wheel vibration is usually the result of one of the following five conditions:

    • Excessive radial runout
    • Excessive lateral runout
    • Excessive imbalance
    • Excessive radial force variation
    • Excessive lateral force variation

These conditions must be eliminated one at a time in order to attain a set of tires that are free from vibration causing elements. Substitute a set of tires from another vehicle only as a last resort, and only after the tires have been tested on a similar vehicle under the same conditions. Correcting the existing tire and wheel assemblies is the most accurate and least time consuming approach. This is due to vehicle-to-vehicle sensitivities and the differences between the hubs of any two vehicles.

Methods of Measuring Tire/Wheel Assembly Runout

The tire and wheel assembly runout will directly affect the amount of the imbalance and the radial force variation. Therefore, correct the runout first before further diagnosis. The less runout, the less imbalance and radial force variation. Radial and lateral runout can be corrected at the same time. There are two methods for correcting the tire and wheel assembly runout:

    • The on-vehicle method, with the tire and wheel assembly mounted on the hub. The wheel bearing must be in good condition.
    • The off-vehicle method, with the tire and wheel assembly mounted on a spin-type tire balancer.

Perform the following initial on-vehicle inspections prior to the off-vehicle runout checks:

  1. Inspect the tires for any uneven bead seatings. The distance from the edge of the ring to the concentric rim locating ring should be equal around the entire circumference.
  2. Properly mount the tires if the beads are not seated properly in order to avoid excessive runout and imbalance.

Object Number: 95617  Size: SH

The off-vehicle method is the easiest way of measuring the tire and wheel runout. Properly mounting the dial indicator in the correct location in relation to the tire (1) is easier. The dial indicator is less likely to be subjected to water, snow, dirt, or other elements. After measuring the correct runout off-vehicle, inspect the runout with the tire and wheel assembly mounted on the vehicle. The runout measurement may vary greatly between these two methods. If so, the runout is due to one of the following conditions:

    • Stud circle runout
    • Hub flange runout
    • A mounting problem between the wheel and the vehicle

Measuring Tire/Wheel Assembly Runout

If the vehicle has been sitting in one place for an extended period of time, the tires may develop flat spots at the point where the tires were resting on the ground. These flat spots will affect the runout readings. In order to eliminate these flat spots, drive the vehicle long enough to warm up the tires. The flat spots must be eliminated prior to taking any runout measurements.

Measurement Procedure

  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Obtain an initial indication of how much runout exists:
  3. 2.1. Spin the each tire and wheel assembly on the vehicle by hand (or at a slow speed using the engine to run the drive wheels).
    2.2. Visually inspect the amount of runout from the front or rear of the tire.
  4. Matchmark the each of the tire and wheel assemblies in relation to the wheel studs and to their position on the vehicle (LF, LR, RF, RR) for future reference.
  5. Remove the tire and wheel assemblies one at a time and mount on a spin-type wheel balancer. Refer to Wheel Removal in Tires and Wheels.
  6. Locate the tire and wheel assembly on the balancer with a cone through the back side of the center pilot hole.


    Object Number: 176957  Size: SH
  7. Wrap the outer circumference of tires that use an all-season or aggressive tread pattern with tape (1), in order to accurately measure the radial runout.
  8. Measure the tire and wheel assembly radial runout.
  9. 6.1. Slowly rotate the tire and wheel assembly one complete revolution and ZERO the dial indicator on the low spot.
    6.2. Rotate the assembly one more complete revolution and note the total amount of runout indicated.

    Maximum Radial Runout

        • Measured off-vehicle: 1.27 mm (0.050 in)
        • Measured on-vehicle: 1.52 mm (0.060 in)

    Object Number: 176958  Size: SH
  10. Measure the tire and wheel assembly lateral runout.
  11. Lateral runout should be measured on a smooth area of the sidewall as close to the tread as possible. Ignore any jumps or dips due to sidewall splices and attain an average amount of runout.

    7.1. Slowly rotate the tire and wheel assembly one complete revolution and ZERO the dial indicator on the low spot.
    7.2. Rotate the assembly one more complete revolution and note the total amount of runout indicated.

    Maximum Lateral Runout

        • Measured off-vehicle: 1.27 mm (0.050 in)
        • Measured on-vehicle: 1.52 mm (0.060 in)
  12. Make the necessary repairs to the tire and wheel assembly.
  13. Install the tire and wheel assembly to the vehicle. Refer to Wheel Installation in Tires and Wheels.
  14. Repeat the procedure until all the wheel runouts have been measured.
  15. Lower the vehicle.

Measuring Wheel Runout

If tire and wheel assembly runout cannot be brought within tolerance, measure the wheel runout.

If any runout measurement of a wheel exceeds specifications, the wheel should be replaced. (ALWAYS measure the runout of a new wheel.)

If the runout of the wheel is within tolerance, and the tire and wheel assembly runout cannot be reduced to an acceptable level, the tire should be replaced. (ALWAYS measure the tire and wheel assembly runout after replacing the tire.)

Measurement Procedure

  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Matchmark the each of the tire and wheel assemblies in relation to the wheel studs and to their position on the vehicle (LF, LR, RF, RR) for future reference.
  3. Remove the tire and wheel assemblies one at a time and mount on a spin-type wheel balancer. Refer to Wheel Removal in Tires and Wheels.
  4. Locate the tire and wheel assembly on the balancer with a cone through the back side of the center pilot hole.


    Object Number: 176966  Size: SH
  5. Measure the wheel radial runout on the outside of the wheel (with the tire mounted), if the wheel design allows.
  6. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.

    4.1. Slowly rotate the tire and wheel assembly one complete revolution and ZERO the dial indicator on the low spot.
    4.2. Rotate the assembly one more complete revolution and note the total amount of runout indicated.

    Maximum Radial Runout

        • Steel Wheel--1.015 mm (0.040 in)
        • Aluminum Wheel--0.762 mm (0.030 in)

    Object Number: 176968  Size: SH
  7. Measure the wheel lateral runout on the outside of the wheel (with the tire mounted), if the wheel design allows.
  8. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.

    5.1. Slowly rotate the tire and wheel assembly one complete revolution and ZERO the dial indicator on the low spot.
    5.2. Rotate the assembly one more complete revolution and note the total amount of runout indicated.

    Maximum Lateral Runout

        • Steel Wheel--1.143 mm (0.045 in)
        • Aluminum Wheel--0.762 mm (0.030 in)
  9. If the wheel design does not allow runout measurements to be made with the tire mounted, dismount the tire from the wheel. Refer to Tire Mounting and Dismounting in Tires and Wheels.

  10. Object Number: 176960  Size: SH
  11. Measure the wheel radial runout on the inside of the wheel.
  12. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.

    7.1. Slowly rotate the wheel one complete revolution and ZERO the dial indicator on the low spot.
    7.2. Rotate the wheel one more complete revolution and note the total amount of runout indicated.

    Maximum Radial Runout

        • Steel Wheel--1.015 mm (0.040 in)
        • Aluminum Wheel--0.762 mm (0.030 in)

    Object Number: 176964  Size: SH
  13. Measure the wheel lateral runout on the inside of the wheel.
  14. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.

    8.1. Slowly rotate the wheel one complete revolution and ZERO the dial indicator on the low spot.
    8.2. Rotate the wheel one more complete revolution and note the total amount of runout indicated.

    Maximum Lateral Runout

        • Steel Wheel--1.143 mm (0.045 in)
        • Aluminum Wheel--0.762 mm (0.030 in)
  15. Make the necessary repairs to the tire and wheel assembly.
  16. Install the tire and wheel assembly to the vehicle. Refer to Wheel Installation in Tires and Wheels.
  17. Repeat the procedure until all the wheel runouts have been measured.
  18. Lower the vehicle.

Vectoring

Vectoring is a technique used to reduce radial or lateral runout -- and to even dynamic balance on the tire and wheel assemblies. Vectoring can be accomplished by the positioning of the tire on the wheel and the positioning of the tire and wheel assembly on the hub/rotor.

Tire To Wheel Vectoring (Excessive Wheel Runout)

Do the following to reduce radial/lateral runout (wheel is major contributor):


    Object Number: 968  Size: SH

    Important: Always rebalance the tire and wheel assembly after vectoring.

  1. Determine visually which runout needs to be minimized.
  2. If the radial runout is the problem, take a measurement on the center tread rib.
  3. If the tread is uneven, wrap tape tightly around the tire, record the runout magnitude, and mark the high spot location (4).
  4. If the lateral runout is the problem, take a measurement on the sidewall just below the edge of the tread shoulder.
  5. Record the runout magnitude and mark the high spot location (4).
  6. Mark the tire sidewall at the valve location (3).
  7. • This is the 12 o'clock position (6).
    • The location of the high spot is always with respect to the clock location on the wheel.
  8. Break the tire and wheel assembly down on a tire mounting machine and rotate the tire 6 hours (180 degrees) on the rim (8).
  9. • Reinflate the tire and measure the runout in question.
    • Record the magnitude and location of the high spot (valve stem is 12 o'clock) (7).
  10. If the clock location of the high spot remained at or near the clock location of the original high spot, the rim is the major contributor to the runout problem (4, 7).
  11. • Confirm by removing the tire from the wheel and check the wheel rim runout.
    • If the wheel rim runout exceeds specification, replace the wheel.

Tire To Wheel Vectoring (Excessive Tire Runout)

Do the following to reduce radial/lateral runout (tire is major contributor):


    Object Number: 969  Size: SH

    Important: Always rebalance the tire and wheel assembly after vectoring.

  1. Determine visually which runout needs to be minimized.
  2. If the radial runout is the problem, take a measurement on the center tread rib.
  3. If the tread is uneven, wrap tape tightly around the tire, record the runout magnitude, and mark the high spot location (3).
  4. If the lateral runout is the problem, take a measurement on the sidewall just below the edge of the tread shoulder.
  5. Record the runout magnitude and mark the high spot location (3).
  6. Mark the tire sidewall at the valve location.
  7. • This is the 12 o'clock position (4, 6).
    • The location of the high spot is always with respect to the clock location on the wheel.
  8. Break the tire and wheel assembly down on a tire mounting machine and rotate the tire 6 hours (180 degrees) on the rim (7).
  9. • Reinflate the tire and measure the runout in question.
    • Record the magnitude and location of the high spot (valve stem is 12 o'clock) (7).
  10. If the clock position of the high spot is 6 hours from the original high spot, the tire is the major contributor of the runout problem. Replace the tire (3, 8).
  11. After correcting the tire to wheel vectoring, rebalance the tire and wheel assembly.

Tire And Wheel Assembly To Hub/Rotor Vectoring

This compensates for any imbalance in the brake rotor, drum, or wheel cover. Do the following to reduce radial/lateral runout:


    Object Number: 970  Size: SH
  1. Mark the wheel hub bolt nearest to the valve stem for reference (1).
  2. Rotate the assembly two wheel hub bolts and recheck the runout (2).
  3. • Several positions may have to be tried to locate the optimum position.
    • This can be effective for both radial and lateral runout.
  4. If there is some looseness in the wheel hub bolt holes, radial runout can be reduced by loosening the hub bolt nuts slightly, moving the wheel position on the bolts and then retightening the nuts.
  5. Balance the tire and wheel to the hub/rotor assembly.